Field of Invention. The present invention relates to the field of downhole tools used in a subterranean wellbore. More specifically, the invention relates to a system and method which enables the control of multiple tools deployed in such a wellbore with the use of only one hydraulic control line.
It is common to deploy hydraulic control lines in subterranean wellbores, such as oil wells, in order to control downhole equipment. Packers, valves, and perforating guns are some of the downhole tool types that can be controlled by changes in pressure in the fluid contained in the hydraulic control lines. In some prior art systems, multiple control lines are deployed in the wellbore to control multiple downhole tools. Typically the top end of each control line extends to the surface (land or sea floor) and is connected to a hydraulic pump that can control the pressure of the fluid inside the line.
A control line must be passed through a feedthrough of a packer in order to extend the control line from the top to the bottom of the packer (or across the packer). Among others, a function of a packer is to seal the wellbore annulus across the packer. However, each time a control line is extended through a feedthrough, a potential leak path is created in the packer potentially allowing the seal created by the packer to fail. Therefore, the prior art would benefit from a system that decreases the number of control lines necessary to control multiple downhole tools.
Thus, there is a continuing need to address one or more of the problems stated above.